This disclosure concerns an invention relating generally to the manufacture of tiles for floors, walls, and other surfaces, and more specifically to the custom manufacture of such tiles for use in conjunction with preexisting mass-manufactured tiles.
Laminate (more commonly known as plastic laminate) is a product which has been used in this country for decades as a countertop surface or a veneer for numerous articles of furniture, cabinetry and other architectural features. Laminate flooring (also known as plastic laminate flooring) was first introduced in the United States around 1994 by the Swedish company Pergo AB. Its initial product line consisted of planks made of laminated wood which were approximately 8xe2x80x3 wide and 48xe2x80x3 long, and which came in an assortment of wood tone finishes. Since that time, many other companies (such as Formica Corporation and Wilsonart International) have manufactured plastic laminate, and it is now an exceedingly popular floor covering.
Laminate flooring consists of layers of different materials, generally wood and/or wood byproducts/composites, which include an upper plastic laminate layer. The plastic laminate layer can be made to look like materials such as wood, stone, marble and cork by various printing methods. The specific finish that the floor is to replicate is printed on a layer which is incorporated into the plastic laminate. The plastic laminate is then adhered to a substrate of wooden or wooden composite material. To make the finished surface durable, a tough wear layer is applied to the laminate surface.
Typically, the wear layer, laminate layer and substrate layer are produced in 4xe2x80x2 by 8xe2x80x2 sheets in a linear production line prior to their being resized into elongated plank-like flooring tiles. A sheet moves along a conveyor to different stations to be cut to the rough shape and size of the tiles. The sheet is often first cross-cut to produce two 4xe2x80x2 by 4xe2x80x2 sections, and is then gang-ripped to produce planks. The planks continue along the conveyor and are fed into a molder, which has a series of cutters set in a straight line array in order to profile a tongue along one side edge of the plank and a groove along the opposite side edge of the plank. The pieces are then rotated by means of the conveyor and are fed into the next machine, which adds a tongue to one end edge of the plank and a groove to the opposite end edge of the plank. The resulting planks are then suitable for installation on a floor (or other surface) by fitting a tongue of one plank into the groove of an adjacent plank.
Wood flooring is manufactured in much the same way, but solid wood flooring is generally not initially cut into standard-size larger sheets. Rather, it is milled into board widths determined by the girth of the tree from which they came. Engineered wood flooring is more similar to laminate flooring in that a surface layer or veneer of a wood species is adhered to a substrate of either plywood or a composite material, and such engineered wood flooring may be initially laid up in the 4xe2x80x2 by 8xe2x80x2 format. The machining process for engineered wood flooring is generally similar to that for laminate and wood flooring.
Manufacturing of the aforementioned tiles requires a surprising degree of precision. Tile thicknesses are of critical concern, since tiles that have out-of-tolerance thicknesses, or vertically offset tongues or grooves, generate xe2x80x9cledgingxe2x80x9d: one tile has an edge raised above the surface of an adjacent tile. Apart from being unsightly and potentially dangerous (particularly since upper wear surfaces are generally very tough and can provide a knife-like edge), ledging leads to rapid wear. This is why a tongue and groove or similar interlocking arrangement (such as splines, rabbeted joints, or embedded metal interlocks) is generally needed between laminate tiles; the interlocking arrangement, if properly situated on the tile edges, helps align the top surfaces of laminate tiles in coplanar relationship, even if adhesive is not uniformly applied to the bottoms of adjacent tiles. Additionally, since gaps between adjacent tiles can greatly diminish the appearance of the floor, tight dimensional tolerances must be observed in tile lengths and widths. Prefinished materials such as plastic laminate and wood veneers require a very tight tolerance, whereas installations that are sanded and finishedxe2x80x94such as with wooden floorsxe2x80x94the filler and finish help disguise any gaps related to milling (as well as gaps arising from swelling or contraction). Additionally, any ledging is removed through the sanding process.
An exception to the foregoing forms of manufacturing occurs with decorative elements, such as medallions and feature strips (also known as border strips), for wooden flooring. A medallion may include a predetermined design made up of differently shaped pieces of different types of wood. The pieces of the design are machined from thin layers of wood (usually no more than xe2x85x9xe2x80x3 thick) with their edges perpendicular to the top and bottom surfaces so that they can be adjacently fitted together with no gaps. The pieces are adhered to a substrate which is then cut to the required shape, such as a square, rectangle, circle or ellipse. Thus, medallions are veneered tiles somewhat similar to engineered wood tiles, and the design pieces serve as a decorative top layer for the substrate. Borders are manufactured similarly, but generally use only squares and rectangles for their design pieces. Additionally, borders may include a tongue and groove edge to allow the linear mode of manufacturing. Medallions often do not have a tongue or groove around their edge, and can only be installed as a drop-in feature. In other words, after an entire floor has been installed, a hole can be cut through the installed floor (generally with a router) to accept the medallion, which is then glued in place. Decorative elements are mass produced, and various lines of elements are available in stores and catalogs for installation in wooden floors.
As of 2001, decorative elements such as borders and medallions are not known to be used with laminate floors. This is probably owing to several reasons. First, because they are made of different materials than the laminate floors (generally wood or wooden composites), their different appearance is difficult to coordinate with laminates, particularly if their finish changes with age. Second, since the laminates are much tougher, the more significant wear on the wood-based elements would make them stand out more over time. Third, laminates must be cut with great care so that their surfaces do not chip, or so that the laminate planks do not break (which may occur if hole-cutting unduly reduces the width of a laminate plank). This makes it inadvisable to cut holes in laminates to receive decorative elements, since chipping of the laminate floor may necessitate its removal and replacement if damage occurs. Fourth, laminates can be difficult to cut with precision owing to their toughness, making it difficult to cut a hole in a laminate floor which may tightly receive a decorative element. Fifth, unless a decorative element is made of laminate materialsxe2x80x94which is exceedingly difficult for the aforementioned reasonsxe2x80x94the use of a decorative element with laminate floors can lead to gapping and ledging problems owing to different degrees of expansion/contraction between the materials owing to heat and humidity. Sixth, since the thicknesses of laminate floors vary by manufacturer, it would be exceedingly expensive to manufacture decorative elements for all different laminate flooring lines because of the wide variety of decorative elements that would be required. Variations in the widths and lengths of laminate planks generate similar difficulties. It is possible to create a border of sorts for laminate floors by using differently-colored planks (from the same manufacturer) adjacent the walls and bounding the remainder of the floor, but since such borders are uniformly coloredxe2x80x94as opposed to commonly-used variegated border designs, such as checked and mosaic designsxe2x80x94these are rather drab. It is inadvisable to merely cut laminate planks into sections and arrange them into patterns, since the cutting will almost certainly eliminate some or all of the tongue-and-groove engagements between sections, and the interlocking arrangement between sections is needed to help avoid ledging and gaps. Additionally, the aforementioned cameras with chipping and/or gaps arise.
It would therefore be useful to have available methods and apparata for producing decorative elements suitable for use with laminate floors, in particular decorative elements made of laminate material, which avoid or substantially reduce the aforementioned problems.
The invention involves a method of custom manufacture of tiles which may be used in conjunction with preexisting mass-manufactured tiles (such as planks of laminate flooring), with the invention being intended to at least partially solve the aforementioned problems. To give the reader a basic understanding of some of the advantageous features of the invention, following is a brief summary of preferred versions of the method. As this is merely a summary, it should be understood that more details regarding the preferred versions may be found in the Detailed Description set forth elsewhere in this document. The claims set forth at the end of this document then define the various versions of the invention in which exclusive rights are secured.
In a particularly preferred version of the invention, a decorative tile set of nonuniformly-shaped tiles (tiles with non-parallel sides and/or non-perpendicular corners) is manufactured for interlocking installation adjacent uniformly-shaped tiles, i.e., adjacent to tiles having parallel sides and/or perpendicular corners, as in standard flooring tiles such as laminate flooring planks. By xe2x80x9cinterlocking installationxe2x80x9d, this document refers to installation wherein at least a portion of one tile edge is complementarily interfit with the edge of an adjacent tile. Initially, the decorative tile set and each tile therein are defined. For each tile, a tile boundary at the upper surface of the tile is defined wherein the tiles within the tile set are adjacently situated at the tile boundaries. A tile blank boundary is then defined about each tile boundary at the upper surface of the tile by adding an offset region to the tile boundary in one or more directions parallel to the upper surface of the tile.
The invention then makes use of an advantageous means for cutting the defined tiles in the tile set. A sacrificial bed having a planar upper bed surface is provided, and trenches are cut in the sacrificial bed to define areas on the upper bed surface which at least substantially correspond to the tile boundaries. A workpiece from which the tiles within the tile set are to be cut is then provided atop the sacrificial bed. The workpiece has an upper surface corresponding to the upper surfaces of the tiles in the tile set. Preferably, the upper surface of the workpiece is situated in abutment with the sacrificial bed and is secured to the sacrificial bed, as by applying a vacuum from the sacrificial bed. This may be done, for example, by applying a vacuum force to the workpiece from the sacrificial bed, as by making the sacrificial bed porous or otherwise providing apertures in it from which a vacuum force may reach the workpiece (with the vacuum force perhaps being provided by the machine bed of the cutting tool).
The workpiece is then cut to produce tile blanks bounded by the tile blank boundaries. The tile blanks are cut to produce the tiles by forming either male or female interlocking structure on selected tile blanks, with such cutting removing any offset regions to leave tiles bounded at their upper surfaces by the defined tile boundaries. Any male interlocking structure (such as a tongue) is defined in portions of the tile blanks beneath their offset regions, i.e., within the tile blank boundaries and outside the tile boundaries. Any female interlocking structure (such as a groove) is defined in portions of the tile blanks beneath their tile boundaries and their offset regions, i.e., within their tile blank boundaries and their tile boundaries. The cutting of the interlocking structure on each tile blank removes the tile blank""s offset region to conform the tile blank""s upper surface to correspond to the tile boundaries therein.
This cutting of the male and female interlocking structure is advantageously performed by a cutting tool which extends through the planes of the tile blanks and into the trenches of the sacrificial bed. Where the upper surfaces of the tile blanks (and thus the tiles) are held against the sacrificial bed, the holding force helps to maintain the integrity of the upper (finished) surfaces as the cutting tool cuts into them, thereby helping to avoid chipping or other damage to the upper surfaces. In effect, the sacrificial bed reinforces the upper surfaces and helps to protect them in regions within the tile boundaries. Since the cutting tool extends within the planes of the tile blanks and beyond (into the trenches in the sacrificial bed) during cutting, the cutting tool surfaces that provide the cutting are spaced from the tip of the cutting tool (which rests within the trenches), thereby decreasing the likelihood that any flexure in the cutting tool will give rise to imprecision in cutting at the tile blank upper surfaces, decreasing the possibility of gapping between the produced tiles. Beneficially, the foregoing arrangement allows the rapid and inexpensive manufacture of irregularly-shaped tiles with small-radius curves, sharp corners, and other features that would ordinarily be extremely difficult to form in laminate tiles without chipping or breaking, particularly where tongues and/or grooves are also provided near these features.
The tiles within the tile set may then be installed at the same time as the uniformly-shaped tiles, or may instead be installed as an insert within preinstalled uniformly-shaped tiles, as by removing selected uniformly-shaped tiles and inserting the tile set within the space previously occupied by the selected uniformly-shaped tiles.
The invention therefore offers a significant addition to the flooring industry by allowing the manufacture and use of durable decorative tile sets which may be made of the same materials as the floor wherein the decorative tile sets are to be installed, and which may be made to interlock with the floor materials, thereby avoiding irregular appearance/wear and gapping/ledging problems. Since the decorative tile sets may be produced for installation with the preexisting interlocking structure of the surrounding floor (i.e., the surrounding tongues/grooves or other structure), they may be installed alongside the surrounding floor tiles or may be retrofit in the surrounding floor tile with the removal of surrounding floor tile. Additionally, since the decorative tile sets may be made from the same materials as the surrounding floorxe2x80x94i.e., they may be made from materials having the same thicknesses and characteristics, from the same manufacturer, and may even be formed from tiles taken from the surrounding floorxe2x80x94gapping and ledging can be greatly reduced.